I was surprised to learn that UIUC (abbr. for the University of Illinois Urbana-Champaign) has never appeared in any daily New York Times crossword, since most legit or semi-legit four-letter entries have! (The much clunkier YALEU has appeared five times...)

https://www.xwordinfo.com/Finder?word=UIUC (you can also use this site to enter other entries to compare)

General policy for my markets: In the rare event of a conflict between my resolution criteria and the agreed-upon common-sense spirit of the market, I may resolve it according to the market's spirit or N/A, probably after discussion.